Coating thermal noise measurement with a multimode resonator
Lead Research Organisation:
University of Birmingham
Department Name: School of Physics and Astronomy
Abstract
Optical coatings are key components within almost all technology that surrounds us from our glasses to cameras. Extreme-performance coatings are used in optical atomic clocks and gravitaitonal-wave detectors which are the most sensitive clocks and distance meters ever built. Optical coatings are also essential for industrial applications in photonics, particularly for miniaturisation of laser diode devices and for increasing the laser damage threshold.
Optical coatings consist of alternating layers of materials with different refractive indices and are only a few micrometers thick. Their performance is determined by the amount of light scattered and absorbed inside the coating and by their thermal noises caused by the Brownian motion of the atoms. Optical coatings can be manufactured out of a large variety of materials, such as tantalum oxide, silica, and amorphous silicon. However, the ultimate properties of the coatings depend both on the intrinsic properties of these materials and on the manufacturing process. Therefore, it is essential to have a robust experiment to test novel coatings for precision instruments.
We propose to build an internationally-leading facility to directly measure the properties of novel optical coatings. This proposal emanates from two recent findings. First, the MIT LIGO group found that coating samples can be measured in one week using a multimode optical resonator. Second, groups in academia in the UK, USA, and Germany developed a new class of promising extreme-performance coatings for applications in precision measurements. The proposed centre is a crucial step in commercial manufacturing of high-quality coatings since we need to experimentally explore the whole parameter space of coating production, such as deposition rate, doping materials, and annealing temperature.
The key idea of the proposed experiment is to embed a coating sample in the optical resonator and measure its properties using three co-resonating beams. This setup will make all displacement noises common to these beams, except for the coating thermal noises. The main advantage of the proposed facility is that it can test one coating sample per week at the telecom laser wavelength and has the potential to be the first in the world working with extreme-performance coatings in this parameter space. The centre will be able to directly measure coating samples for future optical atomic clocks, next generation of gravitational-wave detectors, fundamental physics experiments and for the commercial applications.
Optical coatings consist of alternating layers of materials with different refractive indices and are only a few micrometers thick. Their performance is determined by the amount of light scattered and absorbed inside the coating and by their thermal noises caused by the Brownian motion of the atoms. Optical coatings can be manufactured out of a large variety of materials, such as tantalum oxide, silica, and amorphous silicon. However, the ultimate properties of the coatings depend both on the intrinsic properties of these materials and on the manufacturing process. Therefore, it is essential to have a robust experiment to test novel coatings for precision instruments.
We propose to build an internationally-leading facility to directly measure the properties of novel optical coatings. This proposal emanates from two recent findings. First, the MIT LIGO group found that coating samples can be measured in one week using a multimode optical resonator. Second, groups in academia in the UK, USA, and Germany developed a new class of promising extreme-performance coatings for applications in precision measurements. The proposed centre is a crucial step in commercial manufacturing of high-quality coatings since we need to experimentally explore the whole parameter space of coating production, such as deposition rate, doping materials, and annealing temperature.
The key idea of the proposed experiment is to embed a coating sample in the optical resonator and measure its properties using three co-resonating beams. This setup will make all displacement noises common to these beams, except for the coating thermal noises. The main advantage of the proposed facility is that it can test one coating sample per week at the telecom laser wavelength and has the potential to be the first in the world working with extreme-performance coatings in this parameter space. The centre will be able to directly measure coating samples for future optical atomic clocks, next generation of gravitational-wave detectors, fundamental physics experiments and for the commercial applications.
People |
ORCID iD |
Denis Martynov (Principal Investigator) |
Publications
Abbott R
(2022)
All-sky, all-frequency directional search for persistent gravitational waves from Advanced LIGO's and Advanced Virgo's first three observing runs
in Physical Review D
Abbott R
(2022)
Search for continuous gravitational wave emission from the Milky Way center in O3 LIGO-Virgo data
in Physical Review D
Abbott R
(2022)
Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run.
in Physical review letters
Abbott R
(2021)
Upper limits on the isotropic gravitational-wave background from Advanced LIGO and Advanced Virgo's third observing run
in Physical Review D
Abbott R
(2021)
Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run.
in Physical review letters
Abbott R
(2022)
Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run
in The Astrophysical Journal
Abbott R
(2022)
Constraints on dark photon dark matter using data from LIGO's and Virgo's third observing run
in Physical Review D
Abbott R
(2022)
Searches for Gravitational Waves from Known Pulsars at Two Harmonics in the Second and Third LIGO-Virgo Observing Runs
in The Astrophysical Journal
Dmitriev A
(2022)
Enhancing the sensitivity of interferometers with stable phase-insensitive quantum filters
in Physical Review D
Description | CTN collaboration |
Organisation | Massachusetts Institute of Technology |
Country | United States |
Sector | Academic/University |
PI Contribution | In Birmingham, we develop an international leading centre for testing of optical coatings at 1550 nm. |
Collaborator Contribution | The University of Strathclyde provides optical coatings for our experiment. Massachusetts Institute of Technology provides expertise in optical coatings and in their measurements. |
Impact | The key outcome is that we have successfully built a facility for testing promising optical coatings. We will develop the experiment further to produce the first measurement of amorphous silicon coating in the world. |
Start Year | 2021 |
Description | CTN collaboration |
Organisation | University of Strathclyde |
Department | Department of Biomedical Engineering |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | In Birmingham, we develop an international leading centre for testing of optical coatings at 1550 nm. |
Collaborator Contribution | The University of Strathclyde provides optical coatings for our experiment. Massachusetts Institute of Technology provides expertise in optical coatings and in their measurements. |
Impact | The key outcome is that we have successfully built a facility for testing promising optical coatings. We will develop the experiment further to produce the first measurement of amorphous silicon coating in the world. |
Start Year | 2021 |
Description | Astonomy in the City, University of Birmingham |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Public/other audiences |
Results and Impact | 150 people attended the University of Birmingham Astronomy in the City event to discuss recent progress in our research field. In the beginning, we delivered a 45 min talk and then the audience asked their questions about science. |
Year(s) Of Engagement Activity | 2021 |
URL | https://www.sr.bham.ac.uk/observatory/astronomyinthecity.php#:~:text=Our%20next%20Astronomy%20in%20t... |